The soil remembers

Andrew Bissett, Project Leader for ‘Microbes and healthy waterways’, contributed to a recent publication in Nature Ecology and Evolution that investigated the legacy of past climates on the current distribution of soil microbial communities.

Soil bacteria are the most abundant and diverse organisms on Earth. They support multiple ecosystem functions including litter decomposition, nutrient cycling, primary production and the regulation of greenhouse emissions.

Because of their enormous functional importance, identifying new predictors that help explain the distribution of soil bacterial community globally is important.

Using data from more than 1000 sites and five separate global and regional datasets, our study provides novel evidence that paleoclimate explains a greater amount of the variation in the richness and composition of bacterial communities than current climate in natural ecosystems.

However, another major result from this study is that the ability of both paleo- and current climate to predict the distribution of soil bacteria declined dramatically in agricultural soils, highlighting the fact that human activities have a strong influence on soil bacterial diversity, for example, by profoundly altering soil properties.

Thus, understanding how agricultural intensification will shift the signature of climatic legacies on microbial communities could improve our ability to evaluate and manage anthropogenic soil disturbances.